Initial commit: Set up Garmin Health Lab project structure

- Initialize monorepo with root workspace configuration
- Set up Express.js backend with TypeScript
- Set up React 18 frontend with TypeScript
- Create database schema with SQLite
- Implement project architecture and documentation
- Add development and deployment guidelines

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

client/src/pages/Dashboard.tsx

@@ -0,0 +1,35 @@
+import React, { useEffect, useState } from 'react';
+import { apiClient } from '../services/api';
+import './Pages.css';
+
+function Dashboard() {
+  const [loading, setLoading] = useState(true);
+  const [summary, setSummary] = useState<any>(null);
+
+  useEffect(() => {
+    const loadData = async () => {
+      try {
+        // TODO: Fetch health summary data
+        setLoading(false);
+      } catch (error) {
+        console.error('Failed to load summary:', error);
+        setLoading(false);
+      }
+    };
+
+    loadData();
+  }, []);
+
+  if (loading) {
+    return <div className="page-loading">加载中...</div>;
+  }
+
+  return (
+    <div className="page">
+      <h2>健康仪表板</h2>
+      <p className="placeholder">仪表板内容即将推出...</p>
+    </div>
+  );
+}
+
+export default Dashboard;